In known methods of this kind (DT-OS 16 90577) the mold is an auxiliary element formed according to the matrix and is, for example, of artificial material, wax or an easily fusible alloy. One thus works with a reproduction of the matrix which necessarily results in inaccuracies. Therefore, the shaping mask obtained by the means of the auxiliary elements does not satisfy requirements for high. This applies also and particularly when, in addition, (DT-OS 19 12312) conductive lacquer and/or separating lacquer is used. On the other hand, modern tool manufacture sets increasingly high standards on precision, particularly with respect to precision-machining tools. These demands can no longer be met using the conventional methods. Consequently, electroerosion tools meeting the precision requirements can no longer be produced by hitherto known methods and therefore can no longer simply be reproduced.